How to correctly do a fluorescent daisy chain...?

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Old 01-29-08, 10:47 PM
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How to correctly do a fluorescent daisy chain...?

Hi there.

First, my question regards assembling lighting that is not for modification to my dwelling. I am building a table that is lit from underneath to expose photosensitive ink in a print studio.

I have ten 40W fluorescent fixtures to hardwire together, and while I've done the simple splice and connect the wires & ground to plug into the wall before, I'd rather daisy-chain these ten fixtures together into one plug and for some reason, even though I've been verbally told before how to accomplish this (black to black, white to white) I can't visually/mentally wrap my mind around how to do it correctly.

Can someone give me some written direction? I have 15A 125V 1875W rated heavy-duty cord to use as my plug. I just can't seem to get how the fixtures connect to each other in order and then to the plug.

Thank you.
 
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Old 01-30-08, 05:14 AM
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All the fixtures have a white, black and green/bare wire. Hook all your whites to white, blacks to black and green/bare to bare, except one. On that one, hook the cord black to the fixture black, and the cord white to the fixture black, and the grounding wires together. How will you be switching this thing? One other thing, if these are to be laid side by side, reverse the position of every other fixture so the wire outlets are adjacent to each other. That way you can connect them using minimal wire between the fixtures.
 
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Old 01-30-08, 05:35 AM
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Larry's directions have a mis-type. He meant to say that the cord white goes to the fixture white.
 
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Old 01-30-08, 10:26 AM
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Ah, I think what everyone seemed to neglect to tell me (not here, but on the phone and elsewhere) was that I needed to use a spool of WIRE to connect the lamps. I kept thinking to myself "there's no output from these fixtures to connect thru".

Funny how the mind doesn't work electrical after woodworking all day...
 
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Old 01-30-08, 11:09 AM
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You cannot use a spool of wire. You need to use the same kind of cable you are using for the cord and plug, and use that from light to light. You cannot have bare wire outside the electrical boxes of the lights.

I also suggest that you sider switches so that you can turn some of the fixtures off if you don't want as much light.
 
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Old 01-30-08, 04:24 PM
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Thanks for the catch, Bob. Sometimes you just can't put into words what you do with your hands daily. And the colors run together, too.
 
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Old 01-31-08, 12:40 AM
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FYI...

When I said "spool of wire" I meant plastic-covered 'cord' I suppose. Really, you wouldn't think someone would leave exposed metal wire flying around, would you?

-Neo
 
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Old 01-31-08, 04:57 AM
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No, I think what Bob was saying (and I would never second guess him), is you can't use a spool of wire. "Wire" to us is a single piece of metal encased in a thermoplastic casing. You will have to use either the entire cord, containing a black, white, and green wire in an over-casing, OR use Non-metallic cable, here again, containing the white, black and bare grounding wire in a casing. You cannot run individual wires between the fixtures. The cord/cable must be contained where it enters/leaves the fixture(s) with a proper cable strain relief. Didn't mean to steal your thunder, Bob, but happened to be here.
 
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Old 02-01-08, 05:16 AM
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Wouldn't it be easier and safer to fit each fixture with a standard grounded power cord w/plug? Use plug strips mounted under the table to connect them.
 
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Old 02-01-08, 12:34 PM
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Rick: I may be wrong, but they may not be in a repeating line, but rather in an array, like a starburst, which would put the cords in different places. But what you say, if they are all in a line would work just as well.
 
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Old 02-01-08, 07:57 PM
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There is no series wiring involved in this case. All the OP wants to do is connect ten 120-volt lights to a 120-volt circuit.

Regardless whether it's a star pattern or a bus, the fixtures are still wired in parallel to the power. Just as if they had been plugged in to separate receptacles.

Orientation of the cords is a matter of convenience.
 
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Old 02-02-08, 06:14 AM
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We weren't suggesting a series wiring, but parallel, tail to head in case the OP wasn't planning on a straight install, as you had suggested. I understand your thinking, but was giving latitude in case the lights weren't in an ordered placement.
 
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Old 02-02-08, 08:18 AM
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Originally Posted by chandler View Post
We weren't suggesting a series wiring ...
I know that, and you know that, but we don't know if the OP knows that. When I see words like "daisy chain," "star," and "array" it may be confusing.

See if this helps (and forgive the cheesy, hurried artwork):

 
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Old 02-02-08, 04:50 PM
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Very professional looking. Maybe he will chime in and let us know if he has grasped our ideas.
 
 

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